That causal claims are context sensitive is uncontroversial; the ranger cites the lightning bolt as the cause of the forest fire whereas the Venusian cites the atmosphere’s being saturated with oxygen (Putnam 1982: 150). Controversy abounds as to whether this context sensitivity is due to the semantics of our causal concept or can be explained away with reference to conversational pragmatics. The traditional counterfactual account of causality (Lewis 1973) indiscriminately cites the oxygen, the lightning bolt, and any and all other events without which the effect would not have occurred as causes of the fire, explaining away any apparent context-sensitivity as the pragmatic selection of the most salient or relevant of all the causes in a given conversational context (Lewis 1986b; Lewis 2000). I will argue that this appeal to conversational pragmatics fails and this fact, coupled with supplementary positive arguments, suggests that the context sensitivity of causal claims is semantic.